import time
incomplete_sign = 50
print( '='*23+'开始下载'+'='*25)
for i in range(incomplete_sign + 1):
    completed = "*"*i
    incomplete = "."* (incomplete_sign - i)
    percentage = (i / incomplete_sign) * 100
    print("\r{:.0f}%[{}{}]".format(percentage,completed,incomplete),end="")
    time.sleep(0.5)
print( "\n" + '='*23+'下载完成'+'='*25)